1. Field
The present disclosure relates generally to measuring stereoscopic quality, and more specifically to determining a quantitative measurement of perceived distortion in a computer-generated object depicted in a stereoscopic computer-generated scene.
2. Related Art
Cinematographic-quality computer animation has evolved to produce increasingly realistic and engaging visual effects. One way that this is accomplished is through the use of stereoscopic filming techniques that simulate human binocular vision by presenting slightly different viewpoints of a scene to a viewer's left and right eye. This technique, also known colloquially as “3D,” can be used to enhance the illusion of depth perception and make objects in a computer-generated scene appear to extend outward from a two-dimensional screen.
In normal human binocular vision, each eye views the world from a slightly different perspective. The difference in the view from each eye, also called parallax, is caused, in part, by the spatial separation between the eyes. The brain is able to combine the different views from each eye and use the parallax between views to perceive the relative depth of real-world objects.
Computer animation stereoscopic filming techniques take advantage of the brain's ability to judge depth through parallax by presenting separate images to each eye. Each image depicts a computer-generated object from a slightly different viewpoint. The greater the parallax between the two images, the closer the computer-generated object appears to the viewer.
One drawback to stereoscopic films is that the shape of computer-generated objects may appear distorted to a viewer sitting in a theater. The amount of distortion may depend on the amount of simulated parallax between the images and the viewer's actual distance from the screen. The computer-generated object may appear to be further distorted due to other visual effects, such as camera weighting or other post-production editing techniques.
In the past, the amount of distortion was qualitatively assessed by a human through visual inspection of the stereoscopically filmed scene. In some cases, overly distorted scenes were further manipulated using post-production techniques. In some cases, overly distorted scenes were re-shot using different scene parameters. The modified or new stereoscopically filmed scene would then be visually inspected again and the degree of distortion could be qualitatively assessed as either better or worse.
The techniques described herein quantify the perceived distortion of computer-generated objects in a stereoscopically filmed, computer-generated scene by defining a stereo-quality metric. The quantifiable stereo-quality metric can be used to assess the relative visual quality of a 3D scene and ensure that the viewer-perceived distortions are within acceptable limits.